Grate



Dc. 26, 1939. A. HOILAND' 2,185,023

GRATE Filed Oct. 29-, 1937 azezz floL'Za/ad INVENTdR.

v burning of fuel of this sort.

Patented Dec. 26, 1939 UNITED" STATES PATENT OFFICE GRATE Albert Hoiland, Fargo, N. Dak.

Application October 29, 1937, Serial No. 171,738

1 Claim.

My invention relates to an improvement in grates, wherein it is desired to provide a fuel supporting device by the use of which inexpensive fuel such as lignite may be readily burned.

In some parts of the country large-deposits of lignite coal and other cheap fuels of this nature are found. These fuels are used to some considerable extent, but the use has been somewhat restricted due to the fact that the fuel is difficult to burn. Lignite coal, for example, usually contains a large percentage of moisture and must be dried considerably before burning. Considerable air is required in the burning of this fuel, and it has been found that the fuel has a tendency to pack tightly together preventing the passage of air therethrough.

It is the purpose of the present invention to provide a grate which is suitable for use in the This grate provides a means of introducing air into the fuel and also provides a manner in which the fuel may bepreheated and accordingly dried. The dried fuelof course will burn very readily when sufficient air is introduced.

It is a purpose of the present invention to provide a means of introducing air into the fuel in a substantially horizontal direction so that the flames are naturally directed toward the sides of the fire pot, creating a greater heating effect than would otherwise be possible. The amount of air introduced varies with the depth of fuel, so that the fuel at the bottom of the bed of fuel will receive a greater amount of air than the fuel near the top of the fuel bed.

It is a purpose of the present invention to provide a device which is mounted in the center of the fire pot so that the fuel to be burned will be positioned between this central device and the side walls of the fire pot. The walls of the furnace will accordingly be thoroughly heated by the fire in intimate contact therewith, and the depth of the fuel bed along the wall thereof is considerably increased for the amount of fuel used.

It is an added feature of my invention to provide a grate which may be rested directly upon the usualv grates normally found in the ordinary furnace. Accordingly, my grate may be added to the usual furnace without necessity of reconstructing the furnaceor of changing the grates. In installing my grate, it is only necessary to provide an open space on the grates in the center of the fire pot, and to insert my grate to rest upon the usual furnace grates substantially at the center of the fire pot.

It is an added feature of my invention to provide a grate which may be formed in sections and built to any desired length to fit a boiler or fire pot of any size. Accordingly, for commercial boilers and the like having large fire pots, the size of the grate may be readily increased without the necessity of building a grate of proper size to fit each separate boiler.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claim.

In the drawing forming a part of my specification:

Figure 1 is a perspective view of my grate in usual form for use in a small fire pot.

Figure 2 is a central cross-sectional View through the grate illustrated in Figure 1, showing the same in place upon the grates of a furnace.

Figure 3 is an exploded view of a sectional grate, the sections of which have been separated.

The grate A is illustrated as having a top plate II! and a series of co-axial rings or bands I I and I2. The ring II is of slightly larger diameter than the top plate II] and is spaced therefrom. The lower band I2 is of larger diameter than the ring'or band II and is spaced from this ring II. The space between the rings or bands II and I2 is greater than the space between the upper band II and the top plate II]. Obviously, the device may be formed with three or more bands such as II and I2, each increasing in thickness. As the rings or bands increase in thickness, the space between the bands also increases, as it is desired to vary the opening between the bands in proportion to the depth of these bands.

It has been found that the deeper the bed of fuel, the more air is required toburn this fuel. Accordingly, the space between superimposed bands is greater near the bottom of the grate than at'the top of the same. The top I II and the bands I! and I2 are held in proper spaced relationship by connecting ribs I3 which are angularly disposed in spaced relationship within the bands I I and III, as illustrated in Figures 1 and 2 of the drawing. These ribs I3 extend from the lowest ring I2 tothe top plate III and extend beneath the top plate at I4 to reinforce the same.

The grate A in use is designed to rest upon the usual grate of a furnace or burner, these grates being diagrammatically indicated at I5 in Figure 2 of the drawing. While the grates are not usually of the type disclosed in Figure 2, in view. of the large number of forms which might be used, these grates are illustrated as being square or rectangular in cross-section.

The side walls I6 of the fire pot ll of the furnace taper inwardly at the bottom in usual formation, and the fuel when introduced into the furnace drops between the grate A and the side walls l6. Of course, in building a fire, kindling of some sort is usually used, and the fuel is heated to the ignition point, and accordingly, when the fire is well under way, the fuel usually surrounds the side walls of the grate and completely covers the same. The top forms a supporting shelf for heating fuel introduced into the fire, and the portion of the fuel above this top Ill cokes thoroughly while drying and burns readily when broken up. It is therefore advisable to introduce new fuel onto the top of the grate A so that the portion of the device may act as a' coking oven to prepare the fuel for burning. Before placing fuel into the fire, it may become customary to break up the coke formed above the top It] and to spread this preheated fuel about the sides of the grate A. The new fuel may then by introduced again onto the top of the grate. In order to provide a grate suitable for fitting any boiler Without providing separate patterns for each size of grate, I provide a grate formed with each sections id as illustrated in Figure 3 of the drawing and central sections 2%, as also illustrated in this figure. The end sections l9 are identical and are formed similarly to a half of the grate illustrated in Figures 1 and 2. In other words, the end sections l9 would be formed similarly to the construction resulting from cutting centrally through the circular grate A, the out extending through the reinforcing ribs IS. The end sections l9 are provided with a semi-circular top 25 and a band 22 of larger diameter than the top 2! and spaced somewhat below the same; A third band or semi-circular ring 23 is spaced a greater distance from the band 22 thanthis band 22 is spaced from the top 2!. Reinforcing "ribs 2 8 connect the bands 22 and 23 with the top 2! to hold these parts in desired spaced relationship. Openings 25 are provided in the reinforcing ribs 24 to accommodate bolts 26 by means of which the sections I9 and 20 can be connected.

The central sections 2%] are formed with atop 27 and with side bars 28 and Bi) which are spaced similarly to the bands 22 and 23. Reinforcing ribs 3! are formed at the ends of the sections 26 for spacing the bars 29 and 30 from the top 2|] and for holding the parts in desired relationship.

A central reinforcing bar member 32 may also be provided if it is desired to provide additional strength. The contour of the ends of thecentral section 20 is identical with the contour of the flat end of the end sections l9 and these sections fit intimately together, being secured in abutting relationship by the bolts 26. Openings 33 are formed in the reinforcing ribs 3| to accommodate reinforcing ribs, 24 of the end sections l9.

the bolts 26 passing through the It is obvious that under the teachingsof this construction, a grate may be formed with a series of central sections 20 interposed between the end.

sections I9 to provide a grate of any desired length. It is also believed obvious that any number of bands or rings such as H and I2 may be formedso that the substantially frustro-conical' grate may be formed of three and more rings rather than two as illustrated; The op'eration'of such a construction would be identical with that previously described. j

In accordance with the patent statutes I have described the principles of construction of my grate, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that this is only illustrative'of a means of carrying out my invention," and that obvious changes may be made within the scope.

sections in proper relationship, and a'center sec-,

tion interposed betweensaid semi-circular.sec-' tions, said center section including :a substantially flat top member extending between said semi-circular fiat topsections, and side bands abutting said bands on said semi-circular sec-' tions, and means securing said center section to said semi-circular sections.

- ALBERT 

